diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
index cdeeece83c0..98eaeaf8ca4 100644
--- a/gdb/aarch64-tdep.c
+++ b/gdb/aarch64-tdep.c
@@ -3367,20 +3367,6 @@ aarch64_get_tdesc_vq (const struct target_desc *tdesc)
   return sve_vq_from_vl (vl);
 }
 
-/* Add all the expected register sets into GDBARCH.  */
-
-static void
-aarch64_add_reggroups (struct gdbarch *gdbarch)
-{
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, float_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
-  reggroup_add (gdbarch, vector_reggroup);
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
-}
-
 /* Implement the "cannot_store_register" gdbarch method.  */
 
 static int
@@ -3636,9 +3622,6 @@ aarch64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   /* Virtual tables.  */
   set_gdbarch_vbit_in_delta (gdbarch, 1);
 
-  /* Register architecture.  */
-  aarch64_add_reggroups (gdbarch);
-
   /* Hook in the ABI-specific overrides, if they have been registered.  */
   info.target_desc = tdesc;
   info.tdesc_data = tdesc_data.get ();
diff --git a/gdb/arc-tdep.c b/gdb/arc-tdep.c
index d6da2886c49..98bd1c4bc0a 100644
--- a/gdb/arc-tdep.c
+++ b/gdb/arc-tdep.c
@@ -1952,20 +1952,6 @@ static const struct frame_base arc_normal_base = {
   arc_frame_base_address
 };
 
-/* Add all the expected register sets into GDBARCH.  */
-
-static void
-arc_add_reggroups (struct gdbarch *gdbarch)
-{
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, float_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
-  reggroup_add (gdbarch, vector_reggroup);
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
-}
-
 static enum arc_isa
 mach_type_to_arc_isa (const unsigned long mach)
 {
@@ -2364,9 +2350,6 @@ arc_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   /* This doesn't include possible long-immediate value.  */
   set_gdbarch_max_insn_length (gdbarch, 4);
 
-  /* Add default register groups.  */
-  arc_add_reggroups (gdbarch);
-
   /* Frame unwinders and sniffers.  */
   dwarf2_frame_set_init_reg (gdbarch, arc_dwarf2_frame_init_reg);
   dwarf2_append_unwinders (gdbarch);
diff --git a/gdb/csky-tdep.c b/gdb/csky-tdep.c
index f1376730c87..feb416a2406 100644
--- a/gdb/csky-tdep.c
+++ b/gdb/csky-tdep.c
@@ -2050,8 +2050,6 @@ csky_init_reggroup ()
 static void
 csky_add_reggroups (struct gdbarch *gdbarch)
 {
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, general_reggroup);
   reggroup_add (gdbarch, cr_reggroup);
   reggroup_add (gdbarch, fr_reggroup);
   reggroup_add (gdbarch, vr_reggroup);
diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index 400ccd6bebf..99a81b98da1 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -4546,13 +4546,6 @@ i386_add_reggroups (struct gdbarch *gdbarch)
 {
   reggroup_add (gdbarch, i386_sse_reggroup);
   reggroup_add (gdbarch, i386_mmx_reggroup);
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, float_reggroup);
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
-  reggroup_add (gdbarch, vector_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
 }
 
 int
diff --git a/gdb/lm32-tdep.c b/gdb/lm32-tdep.c
index f3f1f87d6bb..4a781c394e9 100644
--- a/gdb/lm32-tdep.c
+++ b/gdb/lm32-tdep.c
@@ -59,16 +59,6 @@ struct lm32_frame_cache
   trad_frame_saved_reg *saved_regs;
 };
 
-/* Add the available register groups.  */
-
-static void
-lm32_add_reggroups (struct gdbarch *gdbarch)
-{
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
-}
-
 /* Return whether a given register is in a given group.  */
 
 static int
@@ -540,7 +530,6 @@ lm32_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   set_gdbarch_push_dummy_call (gdbarch, lm32_push_dummy_call);
   set_gdbarch_return_value (gdbarch, lm32_return_value);
 
-  lm32_add_reggroups (gdbarch);
   set_gdbarch_register_reggroup_p (gdbarch, lm32_register_reggroup_p);
 
   return gdbarch;
diff --git a/gdb/m32c-tdep.c b/gdb/m32c-tdep.c
index 94087302892..5a767c9ed52 100644
--- a/gdb/m32c-tdep.c
+++ b/gdb/m32c-tdep.c
@@ -981,11 +981,6 @@ make_regs (struct gdbarch *arch)
   set_gdbarch_dwarf2_reg_to_regnum (arch, m32c_debug_info_reg_to_regnum);
   set_gdbarch_register_reggroup_p (arch, m32c_register_reggroup_p);
 
-  reggroup_add (arch, general_reggroup);
-  reggroup_add (arch, all_reggroup);
-  reggroup_add (arch, save_reggroup);
-  reggroup_add (arch, restore_reggroup);
-  reggroup_add (arch, system_reggroup);
   reggroup_add (arch, m32c_dma_reggroup);
 }
 
diff --git a/gdb/m68hc11-tdep.c b/gdb/m68hc11-tdep.c
index f1133fe6780..9d978d88018 100644
--- a/gdb/m68hc11-tdep.c
+++ b/gdb/m68hc11-tdep.c
@@ -1361,13 +1361,6 @@ m68hc11_add_reggroups (struct gdbarch *gdbarch)
 {
   reggroup_add (gdbarch, m68hc11_hard_reggroup);
   reggroup_add (gdbarch, m68hc11_soft_reggroup);
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, float_reggroup);
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
-  reggroup_add (gdbarch, vector_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
 }
 
 static int
diff --git a/gdb/mep-tdep.c b/gdb/mep-tdep.c
index 8f2f0a3b30d..1ab01c6cbb3 100644
--- a/gdb/mep-tdep.c
+++ b/gdb/mep-tdep.c
@@ -2427,10 +2427,6 @@ mep_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
   set_gdbarch_stab_reg_to_regnum (gdbarch, mep_debug_reg_to_regnum);
 
   set_gdbarch_register_reggroup_p (gdbarch, mep_register_reggroup_p);
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
   reggroup_add (gdbarch, mep_csr_reggroup);
   reggroup_add (gdbarch, mep_cr_reggroup);
   reggroup_add (gdbarch, mep_ccr_reggroup);
diff --git a/gdb/nds32-tdep.c b/gdb/nds32-tdep.c
index 425d7d90d64..a94a03ab2ab 100644
--- a/gdb/nds32-tdep.c
+++ b/gdb/nds32-tdep.c
@@ -343,14 +343,6 @@ nds32_init_reggroups (void)
 static void
 nds32_add_reggroups (struct gdbarch *gdbarch)
 {
-  /* Add pre-defined register groups.  */
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, float_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
-
   /* Add NDS32 register groups.  */
   reggroup_add (gdbarch, nds32_cr_reggroup);
   reggroup_add (gdbarch, nds32_ir_reggroup);
diff --git a/gdb/or1k-tdep.c b/gdb/or1k-tdep.c
index 9f7fa2f169f..2b906fa69d3 100644
--- a/gdb/or1k-tdep.c
+++ b/gdb/or1k-tdep.c
@@ -1260,19 +1260,7 @@ or1k_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
     }
 
   if (tdesc_data != NULL)
-    {
-      /* If we are using tdesc, register our own reggroups, otherwise we
-	 will used the defaults.  */
-      reggroup_add (gdbarch, general_reggroup);
-      reggroup_add (gdbarch, system_reggroup);
-      reggroup_add (gdbarch, float_reggroup);
-      reggroup_add (gdbarch, vector_reggroup);
-      reggroup_add (gdbarch, all_reggroup);
-      reggroup_add (gdbarch, save_reggroup);
-      reggroup_add (gdbarch, restore_reggroup);
-
-      tdesc_use_registers (gdbarch, tdesc, std::move (tdesc_data));
-    }
+    tdesc_use_registers (gdbarch, tdesc, std::move (tdesc_data));
 
   /* Hook in ABI-specific overrides, if they have been registered.  */
   gdbarch_init_osabi (info, gdbarch);
diff --git a/gdb/reggroups.c b/gdb/reggroups.c
index 6c38ca743f4..74b981fb5e9 100644
--- a/gdb/reggroups.c
+++ b/gdb/reggroups.c
@@ -90,15 +90,6 @@ struct reggroups
 
 static struct gdbarch_data *reggroups_data;
 
-static void *
-reggroups_init (struct obstack *obstack)
-{
-  struct reggroups *groups = OBSTACK_ZALLOC (obstack, struct reggroups);
-
-  groups->last = &groups->first;
-  return groups;
-}
-
 /* Add a register group (with attribute values) to the pre-defined
    list.  */
 
@@ -119,13 +110,42 @@ reggroup_add (struct gdbarch *gdbarch, struct reggroup *group)
   struct reggroups *groups
     = (struct reggroups *) gdbarch_data (gdbarch, reggroups_data);
 
+  /* The same reggroup should not be added multiple times.  */
+  gdb_assert (groups != nullptr);
+  for (struct reggroup_el *el = groups->first; el != nullptr; el = el->next)
+    gdb_assert (group != el->group);
+
   add_group (groups, group,
 	     GDBARCH_OBSTACK_ZALLOC (gdbarch, struct reggroup_el));
 }
 
-/* The default register groups for an architecture.  */
+/* Called to initialize the per-gdbarch register group information.  */
 
-static struct reggroups default_groups = { NULL, &default_groups.first };
+static void *
+reggroups_init (struct obstack *obstack)
+{
+  struct reggroups *groups = OBSTACK_ZALLOC (obstack, struct reggroups);
+
+  groups->last = &groups->first;
+
+  /* Add the default groups.  */
+  add_group (groups, general_reggroup,
+	     OBSTACK_ZALLOC (obstack, struct reggroup_el));
+  add_group (groups, float_reggroup,
+	     OBSTACK_ZALLOC (obstack, struct reggroup_el));
+  add_group (groups, system_reggroup,
+	     OBSTACK_ZALLOC (obstack, struct reggroup_el));
+  add_group (groups, vector_reggroup,
+	     OBSTACK_ZALLOC (obstack, struct reggroup_el));
+  add_group (groups, all_reggroup,
+	     OBSTACK_ZALLOC (obstack, struct reggroup_el));
+  add_group (groups, save_reggroup,
+	     OBSTACK_ZALLOC (obstack, struct reggroup_el));
+  add_group (groups, restore_reggroup,
+	     OBSTACK_ZALLOC (obstack, struct reggroup_el));
+
+  return groups;
+}
 
 /* A register group iterator.  */
 
@@ -139,8 +159,7 @@ reggroup_next (struct gdbarch *gdbarch, const struct reggroup *last)
      creation.  If there are no groups, use the default groups list.  */
   groups = (struct reggroups *) gdbarch_data (gdbarch, reggroups_data);
   gdb_assert (groups != NULL);
-  if (groups->first == NULL)
-    groups = &default_groups;
+  gdb_assert (groups->first != NULL);
 
   /* Return the first/next reggroup.  */
   if (last == NULL)
@@ -171,8 +190,7 @@ reggroup_prev (struct gdbarch *gdbarch, const struct reggroup *curr)
      creation.  If there are no groups, use the default groups list.  */
   groups = (struct reggroups *) gdbarch_data (gdbarch, reggroups_data);
   gdb_assert (groups != NULL);
-  if (groups->first == NULL)
-    groups = &default_groups;
+  gdb_assert (groups->first != NULL);
 
   prev = NULL;
   for (el = groups->first; el != NULL; el = el->next)
@@ -327,15 +345,6 @@ _initialize_reggroup ()
 {
   reggroups_data = gdbarch_data_register_pre_init (reggroups_init);
 
-  /* The pre-defined list of groups.  */
-  add_group (&default_groups, general_reggroup, XNEW (struct reggroup_el));
-  add_group (&default_groups, float_reggroup, XNEW (struct reggroup_el));
-  add_group (&default_groups, system_reggroup, XNEW (struct reggroup_el));
-  add_group (&default_groups, vector_reggroup, XNEW (struct reggroup_el));
-  add_group (&default_groups, all_reggroup, XNEW (struct reggroup_el));
-  add_group (&default_groups, save_reggroup, XNEW (struct reggroup_el));
-  add_group (&default_groups, restore_reggroup, XNEW (struct reggroup_el));
-
   add_cmd ("reggroups", class_maintenance,
 	   maintenance_print_reggroups, _("\
 Print the internal register group names.\n\
diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c
index 8713652b099..79b81351039 100644
--- a/gdb/riscv-tdep.c
+++ b/gdb/riscv-tdep.c
@@ -3497,21 +3497,11 @@ riscv_find_default_target_description (const struct gdbarch_info info)
   return riscv_lookup_target_description (features);
 }
 
-/* Add all the expected register sets into GDBARCH.  */
+/* Add all the RISC-V specific register groups into GDBARCH.  */
 
 static void
 riscv_add_reggroups (struct gdbarch *gdbarch)
 {
-  /* Add predefined register groups.  */
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
-  reggroup_add (gdbarch, vector_reggroup);
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, float_reggroup);
-
-  /* Add RISC-V specific register groups.  */
   reggroup_add (gdbarch, csr_reggroup);
 }
 
diff --git a/gdb/xtensa-tdep.c b/gdb/xtensa-tdep.c
index 62be13643b2..6e478ee893d 100644
--- a/gdb/xtensa-tdep.c
+++ b/gdb/xtensa-tdep.c
@@ -734,23 +734,12 @@ xtensa_init_reggroups (void)
 static void
 xtensa_add_reggroups (struct gdbarch *gdbarch)
 {
-  int i;
-
-  /* Predefined groups.  */
-  reggroup_add (gdbarch, all_reggroup);
-  reggroup_add (gdbarch, save_reggroup);
-  reggroup_add (gdbarch, restore_reggroup);
-  reggroup_add (gdbarch, system_reggroup);
-  reggroup_add (gdbarch, vector_reggroup);
-  reggroup_add (gdbarch, general_reggroup);
-  reggroup_add (gdbarch, float_reggroup);
-
   /* Xtensa-specific groups.  */
   reggroup_add (gdbarch, xtensa_ar_reggroup);
   reggroup_add (gdbarch, xtensa_user_reggroup);
   reggroup_add (gdbarch, xtensa_vectra_reggroup);
 
-  for (i = 0; i < XTENSA_MAX_COPROCESSOR; i++)
+  for (int i = 0; i < XTENSA_MAX_COPROCESSOR; i++)
     reggroup_add (gdbarch, xtensa_cp[i]);
 }